For as long as I can remember, I've been having issues with scrolling in Windows and its applications. When scrolling via dragging the scroll blob, it seemed as if Windows had the annoying habit of randomly resetting your scroll blob to its starting position, which irritated me to no end. It took me a while to figure out, but I finally know when this behaviour occurs - now I just need to know: why?!

By extension, you could also make the blob non-proportional, and have it have a fixed size, but this takes valuable information away.

I believe this is why Windows acts this way. In Windows 3.x and earlier, scrollbars were non-proportional, and it made sense. With proportional scrollbars, previous behavior was carried forward. I don't know if this will be revisted someday, but it probably should be.